mandrake 7.0 upgrade fail: SecurityPolicy / pwgetuid_r?

[Ben Luey <lueyb@gridley.ACNS.Carleton.edu>]

I have RedHat 6.0 and I'm trying to upgrade to mandrake 7.0. I downloaded
all the files and made the boot disk with hd.img. It boots fine and I
select upgrade and it searches for all the  packages to upgrade. When it
gives the dialog box for number of packages remaining and estimated time,
it works for a long time before displaying anything, and then it says is
recieved  an error, shutingdown system. The only messages I could find
once X closes are:

 error opening securitypolicy file
/usr/X11R6/lib/X11/xserver/SecurityPolicy
 getpwuid_r() no such users 0
 shmget fialed at perl-install/install_steps_gtk.pm  line 757

Any ideas?

Ben